In my garden column for The Baltimore Sun this week, I write about my misadventures with ladybugs.

I tried -- not very successfully -- to introduce more than a thousand of the aphid-eating machines into my garden.

Seemed like a good idea at the time.

Anyway, ladybugs are not the only beneficial garden insects. And they are not the only ones you can actually purchase - on line.

Some others:

Green lacewings. The adult eats only pollen, but the larvae are known as "aphid lions" because of their voracious appetites, devouring more than 10,000 aphids in a day. They remain larvae for up to 21 days, just looking for food, which includes mealybugs, cottony cushion scale, spider mites, caterpillars, whitefly larvae and moth eggs.

Praying mantids. These guys eat beetles, caterpillars, grubs, aphids, grasshoppers and crickets. Since they don't fly, they stay right where they are released. Each egg case contains about 200 eggs.

Beneficial nematodes. These microscopic creatures destroy pests that live underground, such as Japanese beetles, cut works, wire worms, weevils, white grubs, fungus gnat larvae, flea larvae, termites -- more than 230 different bugs. They are harmless to people, pets and the environment.

Decollate snails: This wet spring has been heaven for slugs, and they have chewed my hosta into lace doilies. But this is a good snail that eats the common brown garden snail and its eggs.

For more information on good garden pests, visit the Orcon Web site, a site for organic treatments for pests.

Photo credit: Baltimore Sun/Amy Davis